The invention relates to the manufacture of a color cathode-ray tube (CRT) and, more particularly to an apparatus for depositing a metal layer on a faceplate panel of the color cathode-ray tube (CRT).
In the method of applying a metal layer on the screen of a CRT faceplate panel, a coat of aluminum is applied to the lateral interior surface of the panel by vaporization of aluminum pellet when heated. This method has become known in the art as aluminizing the screen. Its primary purpose is to impart to the back surface of the screen the property of specular reflection to the end that maximum brightness may be attained by directing all of the light generated in the screen to the faceplate of the tube.
A mechanical assembly used in this process involves placing the panel over an open end of a vacuum chamber. The vacuum chamber is shaped and dimensioned in accordance with a particular model of faceplate panel. A comparably sized support frame is arranged around the open end of the vacuum chamber to receive and support the panel. A resilient, non-porous gasket is arranged on the support frame to receive a seal edge of the panel. When the chamber is evacuated, atmospheric pressure pushed pushes the seal edge of the panel onto the seal surface of the gasket to form an airtight seal between the gasket and the edge of the panel. Many different size assemblies are needed to accommodate all the different size faceplate panels that are to be manufactured. Accordingly, a new metallization module is provided for applying a reflective aluminum layer to the screen of a cathode-ray tube.
The present invention relates to a metallization module for applying a metal layer on the screen of a CRT faceplate panel. The metallization module comprises a vacuum chamber having sidewalls, a base, an adaptor plate, and a lid. The adaptor plate is positioned between the lid and the sidewalls of the metallization module. Evacuation of the vacuum chamber causes atmospheric pressure to act against the outside surface of the lid, forming an airtight seal between the lid, the adaptor plate, and the top lip of the sidewalls. One or more adjustable rods on the adaptor plate are used to support the faceplate panel within the metallization module.